Spinal implant with attachment system

ABSTRACT

The embodiments of the present disclosure relate to a spinal implant assembly having features to prevent or minimize fixation elements, such as screws, from being dislodged, or from backing out over time and with use. The spinal implant assembly may comprise an implantable body having first apertures for receiving fixation elements. A plate configured to nest against the posterior portion of the implantable body and comprising one or more second apertures can be provided. These second apertures permit access to the head portions of the fixation elements. One or more locking elements are then passed through the second apertures and engage the head portions of the fixation elements. In addition, the plate may comprise an adjustable arm to allow the plate to be used with implantable bodies of different size.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/754,919 filed Jun. 30, 2015, now U.S. Pat. No. 9,468,534, which is adivisional of U.S. patent application Ser. No. 12/941,289 filed Nov. 8,2010, now U.S. Pat. No. 9,066,815, which claims benefit of U.S.Provisional No. 61/259,391, filed Nov. 9, 2009, and entitled “SPINALIMPLANT WITH ATTACHMENT SYSTEM,” the entire contents of which areincorporated herein by reference.

FIELD

The present disclosure relates to orthopedic implants, and moreparticularly, to spinal implants that facilitate fusion of bone segmentsand associated methods.

BACKGROUND

The integrity of the spine, including its subcomponents like thevertebral bodies and intervertebral discs that are well known structuralbody parts forming the spine, are key to a patient's health. These partsmay become crushed or damaged as a result of trauma or injury, ordamaged by disease (e.g., by tumor, auto-immune disease) or as a resultof wear over time or degeneration caused by the normal aging process.

In many instances, one or more damaged structural body parts can berepaired or replaced with a prosthesis or implant. For example, specificto the spine, one method of repair is to remove the damaged vertebra (inwhole or in part) and/or the damaged disc (in whole or in part) andreplace it with an implant or prosthesis. In some cases, it is necessaryto stabilize a weakened or damaged spinal region by reducing orinhibiting mobility in the area to avoid further progression of thedamage and/or to reduce or alleviate pain caused by the damage orinjury. In other cases, it is desirable to join together the damagedvertebrae and/or induce healing of the vertebrae. Accordingly, animplant or prosthesis may be configured to facilitate fusion between twoadjacent vertebrae. The implant or prosthesis may be placed withoutattachment means or fastened in position between adjacent structuralbody parts (e.g., adjacent vertebral bodies).

Typically, an implant or prosthesis is secured directly to a bonestructure by mechanical or biological means. One manner of spine repairinvolves attaching a fusion implant or prosthesis to adjacent vertebralbodies using a fixation element, such as a screw. Most implants andtheir attachment means are configured to provide an immediate, rigidfixation of the implant to the implantation site. Unfortunately, afterimplantation the implants tend to subside, or settle, into thesurrounding environment as the patient's weight is exerted upon theimplant. In some cases, this subsidence may cause the rigidly fixedattachment means to either loosen, dislodge or potentially damage one ormore of the vertebral bodies. Furthermore, after insertion into thevertebral body, the fixation element or fixation system may work itselfloose and/or back out, i.e., withdraw from the vertebral body. Theconsequence of back out or loosening includes improper or incompletefusion, loss of stability, potential risk to the patient, and a separatecostly and often painful revision surgery.

It is therefore desirable to provide a spinal fusion implant that avoidsthe problem of screw loosening or back out over time and with use. Inaddition, it is desirable to provide an implant and associated fixationelements that can account for subsidence that occurs with the implantsubsequent to implantation while also providing rigid fixation.

Although the following discussion focuses on spinal implants orprostheses, it will be appreciated that many of the principles mayequally be applied to other structural body parts within a human oranimal body.

SUMMARY

The present disclosure describes a spinal implant assembly with anattachment system and one or more fixation elements, such as bonescrews. In one embodiment, the attachment system securing the implant toadjacent bone tissue may be configured to prevent or minimize the screwsfrom being dislodged, or from backing out over time and with use.

In one exemplary embodiment, a spinal implant assembly is provided. Theassembly comprises a spinal implant having an upper surface, a lowersurface, an anterior portion, a posterior portion and one or moreapertures within the posterior portion for receiving at least onefixation element. The assembly further comprises a plate configured tonest against the posterior portion of the implant, the plate includingone or more apertures for receiving at least one fixation element.Further, at least one locking element for securing the fixation elementto the plate is provided. The locking element may comprise a pin, cap orplug, for example.

In another embodiment, a spinal implant assembly comprises animplantable body, a plate, and at least one locking element. Theimplantable body comprises an upper surface, a lower surface, ananterior portion, and a posterior portion. The implantable body can beconfigured for midline insertion between vertebral bodies of a patient'sspine. The implantable body may also comprise one or more firstapertures within the posterior portion of the implantable body forreceiving at least one fixation element. The plate is configured to nestagainst the posterior portion of the implantable body and comprises oneor more second apertures permitting access to a head portion of the atleast one fixation element. The at least one locking element is shapedto pass through the at least one or more second apertures and secure theplate to the at least one fixation element based on engaging the headportion of the at least one fixation element.

In yet another embodiment, a method of treating a patient's spinecomprises accessing at least a portion of a patient's spine via aposterior approach. An implantable body is inserted between vertebralbodies of the patient's spine, wherein the body comprises an uppersurface, a lower surface, an anterior portion, a posterior portion, oneor more first apertures within the posterior portion of the body forreceiving a set fixation elements. The implantable body is attached withthe set of elements to the vertebral bodies. A plate is placed onto theimplantable body based on aligning one or more second apertures overhead portions of the set of fixation elements. At least one lockingelement is then inserted through the one or more second apertures intothe head portions of the set of fixation elements.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosure. Additional features of thedisclosure will be set forth in part in the description which follows ormay be learned by practice of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of thedisclosure and together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 illustrates a perspective view of a spinal implant with anattachment system of the present disclosure.

FIG. 2 illustrates a side view of the spinal implant with the attachmentsystem of FIG. 1.

FIG. 3 illustrates a partial cutaway side view of the spinal implantwith the attachment system of FIG. 1.

FIG. 4A illustrates a top-down view of the locking plate of theattachment system of FIG. 1.

FIG. 4B illustrates a side view of the locking plate of FIG. 4A.

FIG. 5 illustrates a side view of the fixation screw system attached tothe locking plate of FIG. 1.

FIG. 6 illustrates a side view of the locking pin of the attachmentsystem of FIG. 1.

FIG. 7A illustrates a perspective rear view of the locking plate of FIG.1.

FIG. 7B illustrates an exploded view of a locking plate assembly of thepresent disclosure.

FIG. 7C illustrates the assembled locking plate assembly of FIG. 7B.

FIG. 7D illustrates a front view of the locking plate assembly of FIG.7B in a first position.

FIG. 7E illustrates a front view of the locking plate assembly of FIG.7B in a second position.

FIG. 8A illustrates a superior cutaway view of the spinal implant withattachment system of FIG. 1 and radiolucent markers.

FIG. 8B illustrates a perspective cutaway side view of the spinalimplant with attachment system of FIG. 8A.

FIG. 9 illustrates a perspective view of another exemplary embodiment ofa spinal implant with attachment system of the present disclosure.

FIG. 10A illustrates a perspective rear view of the attachment system ofFIG. 9.

FIG. 10B illustrates a perspective front view of the attachment systemof FIG. 10A.

FIG. 10C illustrates an exploded view of the attachment system of FIG.10A.

FIG. 11A illustrates a perspective view of a fixation screw of theattachment system of FIG. 9.

FIG. 11B illustrates an enlarged view of the fixation screw of FIG. 11B.

FIG. 12A illustrates a perspective view of a partially assembled spinalimplant with attachment system of FIG. 9.

FIG. 12B illustrates another perspective view of the spinal implant withattachment system of FIG. 12A.

FIG. 13A illustrates a perspective view of the fixation screw andlocking pin of the attachment system of FIG. 12A.

FIG. 13B illustrates a cutaway view of the fixation screw and lockingpin of the attachment system of FIG. 13A.

FIG. 14A illustrates a perspective view of yet another exemplaryembodiment of a spinal implant with attachment system of the presentdisclosure.

FIG. 14B illustrates an exploded view of the attachment system of FIG.14A.

FIGS. 15A-15D illustrate the method of assembling a spinal implant withan attachment system of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

Referring now to FIG. 1, a spinal implant 10 with an attachment system30 of the present disclosure is shown. The spinal implant 10 may beemployed in the cervical region of the spine, in a manner similar to theone described for the cervical implant of U.S. patent application Ser.No. 11/938,476 filed Nov. 12, 2007, entitled “Orthopaedic Implants andProstheses,” which is herein incorporated by reference in its entirety.Although the spinal implant 10 shown herein is configured for use in thecervical region, it is understood that the spinal implant 10 is notlimited to a cervical application, and may be used in a different regionof the spine as well, such as the lumbar or thoracic regions, so long asit is appropriately sized and configured, and the surgical approachtakes into account this specific design.

The spinal implant 10 may include anterior and posterior portions 12, 14and upper and lower surfaces 16, 18 profiled to correspond with theprofile of any bone material to which they are to be secured. As shown,the upper and lower surfaces 16, 18 may further include surfaceenhancements, such as, teeth 20 to enhance bone attachment. In oneembodiment, the teeth 20 may be formed at about a 30 degree angle withrespect to the upper or lower surfaces 16, 18 of the implant 10. Inother embodiments, the teeth 20 can have an angle between about 25 toabout 35 degrees. It is understood, however, that alternative surfacemodifications such as surface roughenings, barbs, spikes, bumps, etc.may also be employed. In one embodiment, the spinal implant 10 defines agenerally wedge shaped structure. The spinal implant 10, however, mayhave other shapes depending on the desired implantation site.

The spinal implant 10 and its components may be formed of any suitablemedical grade material, such as biocompatible metals like stainlesssteel, titanium, titanium alloys, etc. or a medical grade plastic suchas polyetheretherketone (PEEK) or another radiolucent material, ultrahigh molecular weight polyethylene (UHMWPE), etc. If so desired, theimplant 10 may also be formed of a bioresorbable material. Thebioresorbable material may preferably be osteoconductive orosteoinductive (or both).

As shown, the spinal implant 10 may include a central opening or lumen22 extending between the upper and lower surfaces 16, 18 to facilitatebony ingrowth or fusion between adjacent bone segments, such asvertebral bodies. If so desired, the opening 22 may be used to receiveand hold bone graft material.

The spinal implant 10 may include holes 24 for placement of fixationscrews therethrough to secure the spinal implant 10 to adjacent bonetissue. In the embodiment shown, the implant 10 includes three holes 24,one hole being centrally located (i.e., along the center line), and twolaterally located (i.e., aside the center line). One skilled in the artwill appreciate that the implant 10 may comprise any number of holes inany location on the implant 10. For instance, a two-hole version of thespinal implant 10 may be envisioned. Optionally, the implant 10 maycomprise holes 26 for receiving features like a radiologic marker orother imaging marker.

The holes 24 provide a path through which securing means (e.g., fixationelements such as bone screws) may be inserted so as to secure theimplant 10 to respective superior and inferior vertebral bodies (notshown). The holes 24 may be configured to accommodate a variety ofsecuring means, such as screws, pins, staples, or any other suitablefastening device.

The holes 24 of the spinal implant 10 may be configured to permit apredetermined amount of screw toggle (i.e., angular skew) and enable alag effect when the fixation screw 40 is inserted and resides inside thehole or lumen 24. In other words, the holes 24 permit a certain degreeof nutation by the screw 40 and thus the screws 40 may toggle from oneposition to one or more different positions, for instance, duringsubsidence. It also is believed that the predetermined screw toggle(permitted by the clearance between the lumen, or hole 24 and the screw40) promotes locking of the screw 40 to the implant 10 after subsidencesubsequent to implantation. Screw toggle may also be permitted based onthe contours of the head of fixation screws 40, the shape of holes 64and 70 of fixation plate 60, and tolerances of the locking pins 50. Inone embodiment, the predetermined amount of screw toggle may be about 3to 8 degrees, or about 5 to 6 degrees. Alternatively, the holes 24 ofimplant 10 may be configured with little or no clearance to achieverigid fixation.

As shown, the spinal implant 10 may be secured with an attachment system30 comprising one or more fixation screws 40, locking pins 50, and alocking plate 60. The attachment system 30 generally acts as ananti-backout mechanism to prevent the fixation screws 40 from looseningor rotating and backing out over time and with use.

The fixation screws 40 may be self-tapping and self-drilling and may beof a bone-screw-type, such as those well known to skilled artisans. Insome embodiments, the head portion 42 of the fixation screws 40 maycomprise a bored section 48 that can accommodate the locking pins 50. Asalso shown, the bored section 48 may be configured to allow nutation ofthe locking pins 50, and thus, in addition to toggling by fixationsscrews 40, locking pins 50 may also be permitted to have a certaindegree toggling. The amount of respective nutation allowed for thefixations screws 40 and locking pins 50 may be the same or differentdepending upon the desired freedom of toggling. For example, fixationscrews 40 may be permitted a larger degree of nutation, while lockingpins 50 may be permitted a smaller degree of nutation relative to thefixation screws. Of course, in some instances, locking pins 50 may bepermitted the larger amount of nutation relative to the fixation screws40. This feature may be useful to allow the implant 10 to settle insitu, for example, during subsidence. In some embodiments, the boredsection 48 may be a specific depth corresponding to a length of thelocking pins 50, for example, to prevent over insertion.

The locking pins 50 secure the locking plate 60 onto fixation screws 40.In some embodiments, the locking pins 50 are configured for insertioninto the head portion 42 of fixation screws 40. As shown, in someembodiments, the locking pins 50 may comprise a head 52 with a toolopening, such as a contoured bore 58, for receiving an inserter tool(not shown). The locking pins 50 and alternative embodiments are furtherdescribed with reference to FIG. 3.

The locking plate 60 forms a complementary fit with the spinal implant10. As shown, the locking plate 60 may include holes 64, 70 that alignwith the screw holes on the implant 10. The holes 64, 70 may be sizedappropriately to allow or restrict nutation of the locking pins 50. Inaddition, the holes 64, 70 may be configured to provide the same ordifferent amounts of nutation. Thus, the implant 10 can provide a widevariety of toggling configurations depending on its desired usage.

FIG. 2 illustrates a side view of the spinal implant with the attachmentsystem 30 of FIG. 1. As shown, the locking pins 50 and fixation screws40 may be substantially coaxial. As noted, however, one or both oflocking pins 50 and fixation screws 40 may be configured with at leastsome amount of allowed nutation to provide toggle based on predeterminedtolerances and clearances. In other embodiments, the locking pins 50 andfixation screws 40 may be configured with little or no tolerances inorder to be mated rigidly together.

FIG. 3 illustrates a partial cutaway side view of the spinal implantwith the attachment system of FIG. 1. As shown, the locking pins 50 maysit proud atop the locking plate 60. Alternatively, the locking pins 50may sit flush against the locking plate 60, for example, to reduce theoverall profile or thickness of the implant 10.

Referring now to FIGS. 4A and 4B, the locking plate 60 may comprise aplurality of arms. For example, in the embodiment shown, locking plate60 may comprise lateral arms 62 and a central arm 68. Each arm providesa respective aperture 64 and 70 through which locking pins 50 extendinto fixation screws 40. In particular, once appropriately placed on theposterior portion 14 of the implant 10, the apertures 64 and 70 aresubstantially aligned with the bored sections 48 of the fixation screws40. As also shown, these apertures 64 and 70 may be countersunk.

FIGS. 5 and 6 illustrate the relationship of the locking pins 50 to thefixation screws 40 and to the locking plate 60, respectively. Inparticular, FIG. 5 shows locking pin 50 securing locking plate 60 tofixation screw 40. FIG. 6 illustrates an enlarged view of locking pin 50extending through locking plate 60.

FIG. 7A depicts a rear view of one embodiment of the locking plate 60.As shown in detail, the contours and angles of the locking plate aredesigned and sized so as to form a complementary fit to the posteriorportion 14 of the spinal implant 10. It is contemplated that the lockingplate 60 may be sized to provide a suitable overall thickness and weightof the finally assembled and implanted system.

FIGS. 7B-7D illustrate several views of an alternative embodiment of thelocking plate 60 that allows it to accommodate a variety of implantsizes. For example, the central arm 68 may be adjustable, such as heightadjustable, relative to the rest of locking plate 60. As shown, thecentral arm 68 may comprise a tab 72 and knob 74 that fits into a slot76 provided on locking plate 60. In addition to this type oflock-and-key sliding mechanism, a variety of adjustable mechanisms maybe implemented on the locking plate 60. In addition, these adjustablemechanisms may comprise a locking feature to fix the central arm 68 at aspecific location and size.

FIGS. 8A and 8B show various cutaway views of the implant 10 with theattachment system 30. As also shown, the implant 10 may comprise otherfeatures, such as radiological markers 80 or imaging markers.

FIG. 9 illustrates an alternative embodiment of the locking pins 50. Asshown, the locking pins 50 may comprise locking caps 90 that areinserted into the bored section 48 of fixation screws 40. As shown, thelocking caps 90 may comprise a closed top surface. This form of lockingpin may be desirable to permit installation without the need for a tool,for example, using manual force to achieve a press fit or interferencefit.

FIGS. 10A-10C illustrate another view of locking pins 50 as a lockingplug 90. As shown, the locking pins 50 comprise an elongate body 92having multiple legs or finger projections 96 extending from a headportion 94. The finger projections 96 can be configured to be flexible,enabling the surgeon or user to force the projections 96 through thescrew holes 64 and 70 of locking plate 60 and into the bored section 48of fixation screws 40 with some desired amount of external pressure. Theterminal ends of the legs or finger projections 96 may then enlarge asthey enter the bored section 48 of the fixation screw 40 to form a pressfit or interference fit, so that the locking pins 50 are secured to thefixation screw 40 once it is inserted through the locking plate 60.

FIGS. 11A and 11B depict an embodiment of the fixation screws 40. Asshown, a fixation screw 40 may have head portion 42, a threaded shaft44, a self-drilling end 46, and bored section 48. As shown, the boredsection 48 may be configured with a shape to receive a tool forinsertion and shaped to receive the finger projections 96 of the lockingpins 50 shown in FIGS. 10A-10C.

FIGS. 12A and 12B illustrate different perspective views of the spinalimplant 10 and attachment system 30, partially assembled. Asillustrated, the fixation screws 40 are first inserted through thespinal implant 10. The locking plate 60 can then be placed over thespinal implant 10 and fixation screws 40. As shown, the locking pins 50are similar to those illustrated in FIGS. 10A-10C, and thus, are lockingcaps that can be pushed through the holes 64 and 70 of the locking plate60 to secure the entire assembly and implant together.

FIG. 13A shows a partial cutaway view of a fixation screw 40 and anattached to locking cap 50, with the locking plate 60 in between. FIG.13B shows another cutaway view of the same components.

FIGS. 14A and 14B show yet another embodiment of a spinal implant andattachment system of the present disclosure. The spinal implant 10 andlocking plate 60 may be similar to those described above. However, inthis embodiment, the locking pins 50 comprise a locking plug 100. Asshown, the locking plug 100 may comprise a head 102 and an elongate body104 having legs or finger projections 106 extending from the head 102.In addition, the head 102 may comprise a cylindrical body with a centerbore 108 shaped to mate with an insertion tool (not shown). In theembodiment shown, the bore 108 is shaped like a hexagon. However, it isunderstood that any shape or size may be used in the embodiments of thepresent disclosure.

FIGS. 15A-15D conceptually depict a method of assembling the spinalimplant and attachment system of the present disclosure. As shown inFIG. 15A, the spinal implant 10 is provided with fixation screws 40. Thespinal implant 10 may be provided to the surgeon with the screws 40pre-attached, or separately, as desired. After the surgeon places theimplant 10 in the desired location, such as the cervical region of apatient's spine, the surgeon can tighten the screws 40 into thesurrounding bone tissue, thereby securing the implant 10.

As noted, the implant 10 may be configured to permit a predeterminedamount of screw toggle and enable a lag effect when the fixation screw40 is inserted and resides inside the hole or lumen 24. Upon tightening,the lag effect may be observed whereby the implant 10 draws bone tissuetowards itself, which may promote better fusion.

As further noted, the predetermined screw toggle promotes locking of thescrew 40 to the implant 10 after subsidence subsequent to implantation.For example, after surgery, the patient's natural movement will resultin settling and subsidence of bone tissue and the implant 10 in situ. Itis believed that during this process, the weight exerted upon theimplant 10 causes the fixation screws 40 to toggle and consequently lockagainst one or more surfaces of the holes 24 of the implant 10.

To ensure that the implant 10 stays in place over time and with use, thesurgeon may then place the locking plate 60, such as the one shown inFIG. 15A onto the posterior portion 14 of the spinal implant 10.

Once the locking plate 60 has been placed onto the implant 10, thesurgeon may then insert the locking pins 40 through holes 64 and 70provided on the locking plate 60. As noted, these screw holes areconfigured to align with the bores 48 of the fixation screws 40.Although shown in FIG. 15B with a smooth outer elongate body, thelocking pins 50 may have any variety of surface features. For example,it is contemplated the pins 50 may have threads, teeth, barbs, surfaceroughenings, etc. to assist in mating to their respective fixationscrews 40. Where rigid fixation is desired (i.e., the attachment systemdoes not provide toggle), the underside of the locking pins 50 may alsoinclude surfaces features as well in order to provide secure attachmentbetween the locking pin 50 and the plate 60. Furthermore, in someembodiments, the locking pins 50 may be configured to splay and expandthe diameter at least some portion of the head 42 of the fixation screws40

As shown in FIGS. 15C and 15D, the holes 64 and 70 of the locking platemay also be configured to facilitate the insertion of the locking pinsat a specific for mating into the fixation screws 40. FIGS. 15E-15G arethen provided to show various views of a fully assembled spinal implant10 with attachment system.

Some practitioners prefer to allow some degree of movement between theimplant and the adjacent vertebral body after implantation. In that casethe locking pin 50 may be provided with contours on its underside thatallow the pin 50 to nutate and toggle with respect to the contouredopening 64, 70 of the plate 60. This allowed nutation of the locking pin50 may be in addition to or in replacement of toggling by fixationscrews 40. Other practitioners may prefer a more rigid implant assemblythat is firmly locked to the adjacent vertebral body. Accordingly, bothfixation screws 40 and locking pin 50 may be provided with minimal or noallowed toggle. This implant allows either preference.

In the rigidly fixed version, the locking pin 50 may be provided withoutthe contour on its underside (i.e., a relatively flat underside) whilethe opening 64, 70 of the plate 60 would likewise not include a contour.Thus, when secured together, the locking pin 50 and the plate 60 form arigidly locked construct. It will be appreciated that, instead of havingone superior hole and two inferior holes in the implant as shown in thedrawings, the implant may have two superior and one inferior holes, ormay be adapted to have two superior holes and one inferior holes. Aspreviously discussed, the implant 10 may be configured with any numberof holes without departing from the spirit of the invention.

It will also be appreciated that the angular positioning of the variousholes, as described above, allows the present implant 10 to be of arelatively small size and therefore insertable within the intervertebralspace in the cervical region, where space is at a premium, while stillallowing for the securing of the implant 10 by conventional means. Thus,it will be appreciated that the angular positioning of the holes isimportant to the effective operation of the implant 10 and the abilityto “stack” implants in adjacent multilevel procedures without thesecuring means interfering with each other, which can be of majorsignificance in some situations. For example, it is contemplated thatthe holes 24 of the implant 10 may be angularly configured to allow themiddle fixation screw 40 to be placed between the lateral fixationscrews 40 of an implant 10 and attachment system 30 just below it. Thelocking plate 60 provides a means for ensuring the security and locationof the implant 10 once inserted but may be configured to be reversibleso as to allow removal of the fixation screws 40 if a revision isrequired.

Moreover, while a toggle and a rigidly fixed version of the implant 10and screws 40 are described, it is understood that a combination oftoggling and rigid fixation may be accomplished in a single implant 10and attachment system 30. For example, it is possible to provide animplant 10 that allows toggling of one or more screws 40, while alsoallowing rigid fixation of the other of the screws 40.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of thedisclosure provided herein. It is intended that the specification andexamples be considered as exemplary only.

What is claimed is:
 1. An implantable spine stabilization device,comprising: an implantable body configured for insertion betweenvertebral bodies of a spine, the body having an upper surface, a lowersurface, an anterior portion, and a posterior portion, the posteriorportion having one or more apertures for receiving a fixation element; afixation element comprising an elongate shaft and a head portion with anaperture to receive a locking element; a plate configured to mate withthe posterior portion of the body, the plate having one or moreapertures to receive the fixation element; and a locking element forsecuring the fixation element to the plate.
 2. The device of claim 1,wherein the locking element is configured to engage the head portion ofthe fixation element.
 3. The device of claim 1, wherein the implantablebody comprises one or more portals for receiving an imaging marker. 4.The device of claim 1, wherein the one or more apertures at theposterior portion of the implantable body is configured to permit apredetermined amount of nutation by the fixation element.
 5. The deviceof claim 4, wherein the one or more apertures is configured to permitabout 5 degrees of nutation by the fixation element.
 6. The device ofclaim 1, wherein the one or more apertures comprises an apertureconfigured to rigidly seat the fixation element.
 7. The device of claim1, wherein the head portion of the fixation element is configured topermit a predetermined amount of nutation by the locking element.
 8. Thedevice of claim 1, wherein the head portion of the fixation element isconfigured to rigidly receive the locking element.
 9. The device ofclaim 1, wherein the one or more apertures of the plate is configured topermit a predetermined amount of nutation by the locking element. 10.The device of claim 1, wherein the plate is configured to rigidly neston the head portion of the fixation element.
 11. The device of claim 1,wherein the plate comprises an adjustable arm.
 12. The device of claim11, wherein the adjustable arm comprises a locking feature to fix aposition of the adjustable arm.
 13. The device of claim 11, wherein theplate comprises a slot, and the adjustable arm comprises a knob forinsertion into the slot.
 14. The device of claim 1, wherein the lockingelement comprises a cap, pin or plug.
 15. The device of claim 1, whereinthe locking element is configured to sit proud atop the plate.
 16. Thedevice of claim 1, wherein the locking element is configured to seatflush against the plate.